Endotracheal intubation is a medical procedure used to place an airway device (artificial airway) into a patient's trachea or airway. The use of an airway device is mandated in situations where an individual is unable to sustain the natural breathing function or maintain an open airway on his or her own due to unconsciousness, trauma, disease, drugs or anesthesia. Thus, life-saving mechanical ventilation is provided through the airway device which may be in the form of an endotracheal tube (ETT), or a supraglottic airway device such as a laryngeal mask airway (LMA), King Airway, or one of several other commercially available airway devices.
Endotracheal intubation is accomplished by inserting an airway device into the mouth, down through the throat and vocal cords or voice box, and into the trachea. This procedure creates an artificial passageway through which air can freely and continuously flow in and out of a patient's lungs and prevents the patient's airway from collapsing or occluding.
It is very important that the airway device be positioned correctly and maintained in the correct position in the trachea. If the device moves out of its proper position in the trachea and into either the right or left main stem bronchial tube, only one lung will be ventilated. Failure to ventilate the other lung can lead to a host of severe pulmonary complications. Moreover, if the airway device moves completely out of the trachea and into the pharynx, esophagus or completely outside the body, the patient will become hypoxic due to the lack of ventilation to the lungs, a condition which typically results in life-threatening brain injury within a matter of only a few minutes.
Even after an airway device has been positioned correctly, subsequent movement of the patient can lead to inadvertent movement of the device, as hereinabove described. An intubated patient may restlessly move about and may also attempt to forcibly remove an airway device, whether conscious or unconscious, particularly if the patient is uncomfortable or having difficulty breathing, which can lead to panic. Because medical emergencies may occur anywhere, emergency medical service personal (i.e., paramedics) may be called upon to insert airway devices in out-of-hospital emergency settings as well as in hospital settings by emergency department, operating room, and critical care clinicians. Therefore, such unintentional movement is not uncommon, particularly when the patient is moved from an out-of-hospital setting, such as an accident scene, to an emergency department of a hospital. Further, anytime an intubated patient may be moved, for example, not only from an ambulance to a trauma facility, but also from one hospital to another hospital, from one area of the hospital to another area in the same hospital (imaging, laboratory, operating theater), or from a hospital to an outpatient rehabilitation facility, unintentional movement of an airway device is a risk. Even repositioning an intubated patient in a hospital bed may cause unintentional movement of the endotracheal tube.
Inadvertent movement of an airway device may also occur as a result of moving external ventilation equipment, such as a conventional mechanical ventilator or bag valve mask. Typically, the external ventilation equipment is connected to the external end of the device by an air conduit to establish air flow to and from the lungs. Inadvertent pulling on, or other excessive movement of the air conduit, may transfer movement to the airway device, thereby shifting it from its proper position and causing unplanned extubation.
Unplanned extubation is a hazardous and costly problem which studies have demonstrated occurs at an unacceptably high rate. A study completed by Carson et al reports that approximately 950,000 patients are mechanically ventilated in the United States annually. Carson et al., The Changing Epidemiology of Mechanical Ventilation: A Population-Based Study. Journal of Intensive Care Medicine. 2006 February; 21(3): pp. 173-182. A review of the world-wide medical literature suggests that the world-wide rate of unplanned extubation averages approximately 7.31%. Lucas de Silva, Unplanned Endotracheal Extubation in the Intensive Care Unit: Systematic Review, Critical Appraisal, and Evidence-Based Recommendations. Anesth Analg 2012; 114:1003-14. Applying the world-wide average to the U.S. figure above, an estimated 68,000 patients in the United States alone experience an unplanned extubation each year. Such unplanned extubations are costly, not only for patients who experience increased rates of morbidity and mortality, but also for hospitals, physicians and insurance companies who incur the liability costs associated therewith. The annual intensive care unit (ICU) bed cost associated with unplanned extubations in the United States alone is estimated at $2.6 Billion, which includes imaging, pharmacy, and laboratory expenses. (Extrapolated using data from the Carson study referenced above and the cost of long-term care according to the U.S. Department of Health and Human Services National Clearinghouse for long-term care information. See also S. K. Epstein, M. L. Nevins & J. Chung, Effect of Unplanned Extubation on Outcome of Mechanical Ventilation, Am. Journal of Respiratory and Critical Care Medicine, 161: 1912-1916 (2000) which discusses the increased likelihood of long-term care outcome). Moreover, it is not unknown for jury damage awards in personal injury law suits arising from unplanned extubations to be in excess of $35 M. The high incidence of unplanned extubation and the associated increase in healthcare costs implies that an improved restraining system, which has the capacity to resist the application of greater forces which would otherwise result in movement of the airway device, is sorely needed.
Various prior art systems have attempted to address the problem of maintaining an airway device in the correct position and preventing unintentional extubation. The most common approach for securing an airway device (typically, an endotracheal tube) is with adhesive tape. Umbilical tape may be used as an alternative. Both present the same challenges. The tape is tied around the patient's neck and then wrapped and tied around the smooth outside surface of the endotracheal tube itself. Arranged in this fashion, the tape is intended to anchor the endotracheal tube to the corner of the patient's mouth and prevent its unintentional movement. While the use of tape in this manner provides some benefit, the restraint available from the tape usually diminishes because the tape becomes covered and/or saturated with blood, saliva, or other bodily fluids. Consequently, the endotracheal tube may be readily moved from its preferred position in the patient's trachea, and this form of securing an airway device provides inadequate protection against movement resulting from the application of multidirectional forces such as bending, torsional/rotational or substantial lateral forces to the device. Such forces may exceed fifty (50) pounds in magnitude, and, as shown in the results of two studies of the restraint capabilities of current devices and methods set forth in Tables 1 and 2 below, such devices and methods do not provide sufficient resistance to prevent unplanned extubation. Clinically significant movement is defined as longitudinal movement of the airway device in a direction towards or away from the patient's mouth to a point where the tip of the airway device has moved beyond the vocal cords. Typically, such movement is in the range of five (5) to seven (7) centimeters.
Restraint Capabilities of Current Devices and Methods
TABLE 1MedianMinMaxThomas Tube Holder12.982.6422.44Adhesive Tape19.58 3.9639.6Non Adhesive Tape7.482.4227.72Force to Extubate (7 cm movement) in LbsOwens, et al. Resuscitation (2009)
TABLE 2MedianMinMaxAdhesive Tape (Lillehei)19.51525Tube Tamer12.91015Precision Medical8.6710Biomedix Endogrip10.7612Thomas Tube Holder372843Force to Extubate (2 cm movement) in LbsCarlson, et al. Annals of Emergency Medicine 2007
U.S. Pat. No. 5,353,787 issued Oct. 11, 1994, to Price discloses an apparatus having an oral airway for providing fluid communication for the passage of gas from a patient's mouth through his or her throat and into the trachea, the oral airway being releaseably attached to an endotracheal tube for use in combination therewith. While Price's apparatus eliminates the smooth surface of the tube and resists longitudinal movement in relation to the oral airway, the system disclosed by Price does not address the above-identified problem of resisting multidirectional forces. Moreover, Price's device cannot prevent clinically significant movement of an airway device in relation to the vocal cords and an unplanned extubation resulting therefrom.
Other attempts to solve the aforementioned problems have employed auxiliary mechanical securing devices to maintain the position of an endotracheal tube in a patient. Many of these auxiliary mechanical devices include some type of faceplate which is attached to the patient's face, usually with one or more straps that extend around the back of the patient's head or neck. The faceplate includes some type of mechanical contact device that grips the smooth surface of the endotracheal tube. Typical mechanical contact devices include thumb screws, clamps, adhesives, locking teeth, and straps. By way of example, U.S. Pat. No. 4,832,019 issued to Weinstein et al. on May 23, 1989, discloses an endotracheal tube holder which includes a hexagonally-shaped gripping jaw that clamps around the tube after it has been inserted into a patient's mouth and a ratchet-type locking arrangement designed to retain the gripping jaw in position around the tube. Weinstein's patent disclosure states specifically that the tube will not be deformed. However, the fundamental mechanics of a hexagonal receptacle applied around a cylindrical tube to stabilize it reveal that the hexagonal structure will not impart force to the tube of sufficient magnitude to prevent longitudinal movement. However, it has been found that if sufficient pressure is applied directly to the tube by the gripping jaw, the tube will deform or even crush, thereby decreasing ventillatory efficiency to the point that airflow to the patient's lungs will be restricted or even cut off, an extremely serious problem.
U.S. Pat. No. 7,568,484 issued on Aug. 4, 2009, and U.S. Pat. No. 7,628,154 issued on Dec. 8, 2009, both to Bierman et al., disclose endotracheal tube securement systems which include straps extending from the corners of a patient's mouth above and below the patient's ears on each side of the patient's head. However, the devices disclosed in the '484 and the '154 patents merely retain the position of the tube in the patient's mouth and cannot prevent movement thereof in various directions, either longitudinally, rotationally or laterally, as hereinabove described.
Specifically, to maintain an effective restraint, attending medical personnel increase the amount of clamping force applied on an airway device. Increasing the amount of clamping force to an effective level may pinch the device to the point where a portion of the inner tube diameter (and hence air passageway) is significantly restricted. Restricting the cross-sectional size of the air passageway decreases the ventilatory efficiency of the tube, thereby decreasing the respiratory airflow. The restriction of the cross-sectional size of the air passageway creates resistance to both inspiratory airflow and expiratory airflow. Insufficient airflow during inspiration can lead to hypoxemia, which is problematic, but can be overcome by increasing the positive pressure of the ventilation source. However, during expiration, any increased pressure due to constriction or decreased tube diameter, increases the amount of work a patient must perform to simply exhale. Increased pressure can also lead to barotrauma in the lungs and resistance to expiratory airflow can lead to multiple other adverse effects within the lungs. Impairing a patient's ventilations may result in serious medical effects, particularly with patients whose functions are already compromised. Therefore, the ability for clinicians to adequately stabilize an airway device for prevention of unplanned extubation without constriction of the air passageway is crucial for patient safety.
Endotracheal tubes have a standard respiratory connector that serves as a conduit between the endotracheal tube and artificial ventilator for the purpose of maintaining a continuous flow of air from the ventilation source to the patient's lungs. Standard connectors must be tightly seated into the endotracheal tube to avoid unintentional disconnection of the ventilation source from the endotracheal tube during mechanical breathing. When tightly seated, the connector is often difficult for the clinician to remove from the endotracheal tube, when necessary. Therefore, an airway device with a connector that prevents unintentional disconnection, yet allows for quick and easy intentional connection and disconnection is needed.
More recently, U.S. Pat. No. 8,001,969 issued on Aug. 23, 2011, and U.S. Pat. No. 8,739,795 issued on Jun. 3, 2014, both to Arthur Kanowitz, the inventor of the present invention, disclose airway stabilization systems which address many of the problems set forth above. On-going clinical trials of these devices and continuing research into ways of providing even more advanced and rapidly deployable airway stabilization systems have resulted in yet further improvements to the overall design of the system components.
In view of the above, it will be apparent to those skilled in the art from this disclosure that a need exists for an improved airway stabilization system which not only protects an airway device from occlusion and crushing, but also is easier to apply to a patient while at the same time maintains the device in its preferred position in a patient's trachea and prevents clinically significant movement thereof with respect to the vocal cords as a result of the application of multidirectional forces of significant magnitude thereto. The present invention addresses these needs in the art as well as other needs, all of which will become apparent to those skilled in the art from the accompanying disclosure.